This definition was originally for hedging. Don't talk nonsense if you don't understand. They mainly convert huge price fluctuations into tiny basis fluctuations. Used to avoid huge risks. Order transactions are mainly used for physical delivery. After the buyer and the seller hedge. Pricing is how much profit margin is added or subtracted from the transaction price in the final delivery period. To balance the losses of buyers and sellers. It is also a private transaction. There is a clear introduction in the book The Course of Futures Market. You can have a look!